Adjustable support for induction coils



Sept; 9, 1947.

H A. STRICKLAND ADJUSTABLE SUPPORT FOR INDUCTiON COILS 3 shets-sneet 1 Original Filed larch 21, 1941 INVENTOR Harold 4. Mckland .]5'*.;.

ATT R Sept. 9, 1947.

H. A. STRICKLAND, JR 2,427,332

ADJUSTABLE SUPPORT FOR INDUCTIONv COILS Original Filed March 21, 1941 3 Sheets-Sheet 2 INVENTOR HarddAStriddandJn p 1947. H. A. STRICKLAND, JR 2,427,332

. ADJUSTABLE SUPPORT FOR INDUCTION COILS Original Filed March 21, 1941 :5 Sheets- Sheet 3 .DO'I

- INVENTOR 5o 'ifaroldflmcklandh,

ArronNz-ry Patented Sept. 9, 1947 UNITED STATES PATENT OFFICE ADJUSTABLE SUPPORT FOR INDUCTION COILS Harold A. Strickland, Jr., Detroit, Mich, assignor, by mesne assignments, to The Budd Company, Philadelphia, Pa., a corporation of Pennsylvania Application September 18,

1941, Serial No.

Serial No. 495,701

8 Claims.

My invention relates to furnaces for heating by electromagnetic induction, and particularly to those which can be used or are intended for use in the heating of bar or billet stock for forging purposes. In such furnaces, bar or billet stock of either solid or tubular form, and either circular or angular in cross-section, i inserted Within a coil adapted to be supplied with power from an alternating current source, usually a highfrequency alternating current source of considerable voltage, and the power being turned on to the coil, heating currents are set up within the mass of the bar or billet to be heated due to the electromagnetic induction from the coil itself. These currents heat the bar or billet to a forging temperature. commonly called a workpiece.

An object of my invention is to provide means for supporting the induction heating coil of the furnace in firm and stable relationship to the other parts of the furnace. An additional object is to provide a coil support which may be adjusted readily with reference to the furnace door and push-out rod. Still other objects are to provide a coil support which requires a minimum of parts and space for installation, which is readily accessible for adjustment, which holds the coil with a yielding pressure; and which permits complete removal of the coil without structural disorganization.

Other objects will appear on consideration of the accompanying drawings in which:

Figure 1 is a side elevation of the machine of my invention with the principal parts enclosed by the housings of the machine. The heating coil is shown in dotted line in the upper portion of the housing, while the door normally closing the lower part of the housing, has been removed to show a bank of condensers connected with the coil;

Figure 2 is a vertical section on the axis of the heating coil, showing the heating coil and its immediate mounting and housing the remaining portions of the machine being broken away;

Figure 3 is a transverse section, transaxial to the heating coil, taken on line 33 of Figure 2 looking in the direction of the arrows;

Figure 4 is a perspective view of a bridge-piece connected with a heating coil support clamp; and

Figure 5 is a transaxial segmental section showing the bridge-piece of Figure 4 in use in connection with a special heating coil.

Referring now to the drawings, it will be observed that I have made the frame and housing of the furnace machine 30 generally of L-shape Such a bar or billet is as viewed in side elevation, and in form not unlike the operators switchboard of a manuallyoperated telephone system. This is to say that the frame and housing comprise a horizontal branch 3| having a horizontal table-like top 32, and a vertically extending portion 33. I shall not go into the details of frame members and panelings of this frame and housing 30 further than to say that it is constructed of metal of a strength adequate to support the parts which I show and describe as supported thereby and housed therein. Front, side and back door openings 34, 35, and 36 (the latter not shown in form, although it is intended to extend the full length of the back of the housing 30) are provided for ready access to the various instrumentalities supported by and housed within the casing 30, and these openings are provided with suitable closures such as that 31 shown in the door opening 34 of the front of the casing, which closures may be provided, as in common, with suitable hinges and locks for ready manipulation and locking. An opening 38 in the top 32 of the table-like portion BI is closed by a cast foundation member 3! which mounts the heating coil 45. An opening 41 in the lower section of the vertical portion 33 of frame 30 is closed by a backplate 42 which mounts the workpiece gauging and ejecting mechanism and the magnetic core of the coil. A front-plate rising from the region of the foundation plate 39, coacts with the rear-plate 42 in supporting the hood 41. The front plate closes the otherwise open front end of the hood 41. The foundation plate 39, the coacting and surmounted back and front plates 42 and 58 (also castings preferably) and the hood 4'! together constitute a housing unit individual to the heating coil 46 and its immediate appurtenant parts. The front plate 50 is provided with an opening 5| through which the workpieces are fed to the furnace by projecting them axially of the coil 46. A hinged door 52 closes or shrouds this opening during the heating operation.

The heating coil 4!! is formed of hollow conductors 6! preferably of square shape in cross sec tion. Through these coils cooling water in sufiicient volume to cool the coil is passed. Individual turns of the coil are electrically insulated from each other.

Both top and bottom sides of the coil are provided with insulating layers. On the inner side are a plurality of axially extending segments of fire brick 15 which are retained in position in the coil by a plurality of intermediate tubular rails 16, these rails also being provided with brick securingclips or plates 19 which engage the edges of the bricks to retain them in position.

The outer surface of the coil is covered with segmental strips 69 which together completely encase the outer periphery of the coil, protecting the same and providing heat and electrical insulation.

The rail 16 are supported-in position within the coil by means of end attachment device's'comprising outwardly and radially extending supporting studs 83 secured to the ends of the rails 16 which project beyond the ends of the coil 40'.

These studs are passed respectively through slots or holes, as may be preferred, in the outer ends of metal or insulating material, rails 8'4 laid longitudinally over the length of the exterior of coil 40 to project slightly beyond each end. As shown, the rails are of channel cross-section to afford less generation of eddy currents as well as lightness with strength. As the opposite end (the left-hand end, as shown) the projecting ends of work-supporting rails 16 are engaged within the loops 85 of screw-hooks 86', the threaded outer ends of which are carried radiallyth'rough apertures or slots in the opposite ends of the rails 84, there being preferably, though not necessarily, one securing rail 84 for each work-supporting rail 16. When the nuts 81, respectively, on the ends of stud 83 and screw-hooks are tightened up, they hold the outer ends of the rails 15 toward or against the inner surface of the mica cylinder 66 as does the expanding ring" 89. Thus the rails 16 are held in' position throughout their length and firmly hold the fir'ebrick' lining 15 in place. There may be provided as many expanding rings 80 as are neediul to meet the requirements of coil length.

Heating coil 40' with its workpiece-supporting appurtenances is mounted with its axis coinciding with a general horizontal axis A-A of the furnace machine; by supporting it from coil centering C-clarn'ps 98 carried from and forming a part of pedestals 99 erected upon and secured to the cast foundation plate 39 of the t'able-por t'ion 32of' the housing. There are two (or more in case of large coils) of these coil-supporting pedestals '99 spaced apart an adjustable distance to support coils of a number of different axial lengths without relocation upon the foundation plate 39. Reference particularly to Figures and 3" will make clear their construction. The lower portion of the pedestals 99 has a plane of symmetry coincident with the vertical plane of the axis AA upon which the coil i3 is to be centered. It terminates a considerable distance below the axis A-A, a distance sufiicie'nt to per mit the accommodation of coils All of a number of different sizes. It is' provided with integrallyformed' right and left branches I50, -IG'! making equal angles with the vertical plane VV of axis AA. Threaded through the arms Ifi ll, ill! on radial lines intersecting axis A-A are radially adjustable coil supporting studs Hi2, ms. The heads of these studs I32, 503 are located toward coil 40 from the arms 193, HH and support the coil directly upon pads of insulating material l4 secured to the heads. Thus by relatively adjusting studs I02, [03 the axis of a coil 48 of any accommodatable diameter may be placed directly upon the horizontal axis AA of the furnace machine. In this case there is provided only on securing bar 84' for two rails 15, the two rails being bridged together and to the bar 84 by lateral extensions having a rigid insulated connection with bar 84 and taking at their p- 4.. posite ends the studs 83. Thus there is space for pads H34 directly to engage the coil, and more importantly rails 16 may be removed while the coil 43 is yet firml clamped in position.

The C-clamps 98 of these supporting pedestals are comprised of C-arms, as clearly appears in Fig. 3, forked attheir lower ends to straddle the lower portions of pedestals 93 and be pivoted at its on the opposite side of the vertical plane V-V from'the body of the C-clamp. When the clamps 98 are in clamping position, their upper ends HIT lie in the vertical plane V-V, and are provided with a threaded adjusting stud H33, the head 1&9 of which lies toward the coil MI from the upper and i0! with the axis of the stud in the vertical plane V--V. A set screw 98a acting against a stop surface on the base arm IGD limits the upward movement of the clamp 98.

Beyond the head 109 projects a reduced extension of the stud H2 on which is radially slidably mounted a bridge member H3 carrying at its opposite ends pads of insulating material Ii3a. A spring llll'on the reduced section H2 and intermediate head H39 and bridge H3, presses the bridge toward the coil 4%) to achieve y'ieldingly the clamping of it, while a washer and cotter IH prevent the radially movable bridge from dropping from the reduced extension of the stud H2 when the clamp is released.

This clamping arrangement is not only adapted for clamping the coils of different diameters merely through the radial adjustment of stud 188, but also to clamp under different pressures through the adjustment of spring H0. Yet further, however; the structure of bridge member H 3' is such that merely by rotating it on the reduced extension H2 of stud I08, it is adapted to engage with the top of one of the rails 8' 8 instead of engaging between rails 85. See Figures 5 and 6 in this connection. Examination of these will show that pads l l3a are elongated and pro-- vided in their middles with slots l 13b of a dimension adapting them to fit over the top of a rail 84 when bridges H3 are rotated ninety degrees from the position shown in Figure 3. Thus coils having any desired arrangement of bars 84 may be used, and the smaller coils in which there are but three or four rails it and accompanying bars 84 may be accommodated as readily as the larger ones.

The foundation plate or base 39 upon which the coil 40 is mounted through the pedestals 99 is, as has been said, a casting in this embodiment of the invention. It is formed with its upper face l2! on either side of the pedestals, slightly downwardly and inwardly inclined toward the vertical plane VV whereby collected foreign matter or moisture will gravitate toward the center of the plate from both sides and from each end, the ends being similarly inclined. At the center of the plate and surrounding the region 01" mounting of the pedestals in an endless groove I22 which keeps moisture away from the pedes tals and prevents its creeping upon them. The center of the casting is thus a pad I23 upon which the pedestals are mounted. Groove I22 communicates at its axially inner end with a drainage conduit I24 suitably connected to a drain, as will hereinafter appear. The undermargins I25 of base 39' are finished to rest upon the top of table 32 and be secured thereto by suitable bolts. The sides I26 are also finished and receive in overlapping relation the lower edges of the hood 4'! secured thereto by suitable cap screws; These andno' other screws are removed when it is desired to remove the hood and front plate assembly. The ends 121 of the plate receive in overlapped relation and bolted thereto if desired (bolts not shown), the end plates 42 and 50, thereby vertically aligning them with respect to the base 39.

Devices associated with the feeding-in of the workpieces are mounted in connection with the front plate 5!! of the housing of coil 40. Such are the coil mouthpiece 9B and the door 52 and appurtenant instrumentalities. The mouthpiece 96, as has been said, serves to enter the workpieces of bar or rod stock properly upon the axis A-A of the coil 49 and the supporting rails 16. It is by virtue of its susceptibility to removal and replacement from the opening 5|, suited in size to the various sizes of coils and stock. It is suitably bolted in place (bolts not shown) and mounted with a clearance 96a for radial adjustment to precise position on axis AA. On its inner side it is provided with an annular series of axially and inwardly projecting spaced teeth at l35, the inner side walls of which project radially and axially inwardly toward the coil, and the extremities of which have an extent substantially of the same diameter as those circles on which lie the inner. edges of the work-supporting fins 88, while their inner sides meet their inner ends at a relatively sharp angle. All this clearly appears in Figure 3. Thereby these teeth guide the stock accurately into engagement with the fins 88 of the supporting rail 16, preventing impingement upon intermediate transversely-extending walls (this through their inclined inner walls and their extremities), and when the workpiece is pushed out, removed from it foreign matter such as light scale which may have formed (this through the sharp innermost edges). Such foreign matter as is removed falls between the teeth or past their inner extremities and upon the hopper plate I86 which discharges through opening I81 to a chute I38 projected from the opening I81 exteriorly of the machine. Thus no scale or other foreign matter drops to the foundation plate 39.

Viewing now the ensemble of all instrumentalh ties connected with the housing of coil 40, especially with the foundation plate 39 and the front and rear plates 4'2 and 5a which are erected thereon, it will be seen that all of these instrumentalities can be removed as a unit with the housed coil 40, if this be desired, merely by unbolting the foundation plate 39 and the back plate 52 from the faces of the principal housing 30 of the machine, the electrical, water and other connections having been previously broken. It will, of course, be particularly necessary to remove the bus bar system 53 by disconnection at the connectors I33 and appropriate lowering of the bus bars. This makes for convenient major subassembly and shifting of such major subassembly from machines to test bench or back, or substituting one such major subassemblage from one machine in another, and so forth. Normally, however, the subassembly comprising plate 59, door 52, box I93, and hood 41, is the unit received, leaving base 39 and plate 42 on the main frame. This alone gives four-sided access to the coil do as clamped in place.

This application is a division of my copending application Serial Number 411,297, filed September 18, 1941 (now Patent No. 2,365,021, dated December 12, 1944), which is in turn a division of my copending application Serial No. 384,503, filed March 21, 1941, now Patent No. 2,408,350, dated September 24, 1946.

Though only a single form of the invention is illustrated'and described, the invention is not limited thereto but may be embodied in various forms as desired. As various changes in construction and arrangement of parts may be made without departing from the spirit of the invention as will be apparent to those skilled in the art, reference will be had to the appended claims for a definition of the limits of the invention.

I claim:

1. The combination with a coil of a casing therefor, coil supports, said supports comprisin at least three members angularly spaced around said coil and radially adjustable with reference to the supported coil, at least one of said members having a contacting element, rotatable with reference to the member and provided with spaced contacts.

2. The combination with a coil, of supports therefor comprising at least three angularly spaced coil supporting members, one of which includes a bridge element slidably mounted on the member and having displaced coil contacts attached thereto and means for yieldably mounting said element at the outer limit of movement on the member.

3. In combination a base, at least two co-acting and fixed support members mounted on said base, a coil mounted on said co-acting support members, and a third support member movable into engagement with said coil, said third member being pivotally mounted on said base on an axis parallel to the coil axis on one side of the coil axis and being of C-shape and provided with coil clamping means on the side opposite its hinge and opposite said fixed supports, whereby the space beyond the coil opposite the base may be opened for coil removal.

4. In combination a base, rigid support elements adjustably mounted on said base, a coil mounted on said support members and a third support member pivotally mounted on said base on an axis parallel to the coil axis on one side of the coil axis and being of C-shape and provided with coil clamping means on the side op- V posite its hinge and opposite said fixed supports,

said third support member having a yieldable contact element movably mounted thereupon.

5. In combination a base, converging support members symmetrically mounted on said base on either side of an intermediate transverse plane of reference, a coil mounted on said converging support members, a third support member mounted on said base and lying in said plane of reference on the side of said coil opposite from said converging support members, said support members being radially adjustable with reference to said coil, and means tending to prevent rotation of said coil when the supports are in normal holding position.

6. A supporting member for induction heating coils and the like comprising a base, converging support members mounted on said base for engagement with a coil of cylindrical contour, a third support pivotally mounted on said base on an axis parallel to the coil axis on one side of the coil axis and being of C-shape and provided with coil clamping means on the side opposite its hinge and opposite said fixed supports and adapted to engage said coil at a point angularly displaced from said converging support members, each of said supports being radially adjustable with reference to the point of convergence of said converging support members all of said supports being mounted on said base at one side of the coil.

7-. A support member for induction heating coils and the like, having atleast three angularly related support members movable into and out of engagement with a supported coil, a contact element for at least one of. said converging supporting members, said contact element comprising a bridge plate rotatably and axially movable on said member, contact pads transversely positioned at the ends of said bridge member and spring means for. resiliently maintaining the bridge member at the limit of movement on the support member.

8. A support member for induction heating coils and the like, having at least three angularly related support members movable into and out of engagement with a supported coil, a contact element for at least one of said converging support members, said contact element comprising a bridge plate rotatably and axially movable on said member, contact pads transversely positioned' at the ends of said. bridge member and spring means for. resiliently maintaining the bridge member at the limit of movement on the support member, said pads having transverse recesses formed thereon intermediate the ends thereof. 

